function preloadImages() {
	imageArray = new Array;
	for (i=0; i<imageNames.length; i++) {
		j = i*2;
		imageArray[j] = new Image; imageArray[j].src = 'images/' + imageNames[i] + '_off.jpg';
		imageArray[j+1] = new Image; imageArray[j+1].src = 'images/' + imageNames[i] + '_on.jpg';
	}
	window.defaultStatus='';
}

function imageOn(index) {
	thisimage = eval('document.'+imageNames[index]);
	thisimage.src = 'images/'+imageNames[index] +'_on.jpg';
	return changeStatus(index);
}

function imageOff(index) {
	thisimage = eval('document.'+imageNames[index]);
	thisimage.src = 'images/'+imageNames[index] +'_off.jpg';
	return resetStatus();
}

function changeStatus(index) {
	window.status = imageStatus[index];
	return true;
}

function resetStatus() {
	window.status = '';
	return true;
}